/*
 * @(#)HttpHeaderElement.java   0.3-3 06/05/2001
 *
 *  This file is part of the HTTPClient package
 *  Copyright (C) 1996-2001 Ronald Tschal�r
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *  MA 02111-1307, USA
 *
 *  For questions, suggestions, bug-reports, enhancement-requests etc.
 *  I may be contacted at:
 *
 *  ronald@innovation.ch
 *
 *  The HTTPClient's home page is located at:
 *
 *  http://www.innovation.ch/java/HTTPClient/ 
 *
 */

package org.everrest.http.client;

/**
 * This class holds a description of an http header element. It is used by
 * {@link Util#parseHeader(java.lang.String) Util.parseHeader}.
 *
 * @author Ronald Tschal�r
 * @version 0.3-3 06/05/2001
 * @see Util#parseHeader(java.lang.String)
 * @see Util#getElement(java.util.Vector, java.lang.String)
 * @see Util#assembleHeader(java.util.Vector)
 */
public class HttpHeaderElement {
    /** element name */
    private String name;

    /** element value */
    private String value;

    /** element parameters */
    private NVPair[] parameters;

    // Constructors

    /**
     * Construct an element with the given name. The value and parameters are set
     * to null. This can be used when a dummy element is constructed for
     * comparison or retrieval purposes.
     *
     * @param name
     *         the name of the element
     */
    public HttpHeaderElement(String name) {
        this.name = name;
        this.value = null;
        parameters = new NVPair[0];
    }

    /**
     * @param name
     *         the first token in the element
     * @param value
     *         the value part, or null
     * @param params
     *         the parameters
     */
    public HttpHeaderElement(String name, String value, NVPair[] params) {
        this.name = name;
        this.value = value;
        if (params != null) {
            parameters = new NVPair[params.length];
            System.arraycopy(params, 0, parameters, 0, params.length);
        } else
            parameters = new NVPair[0];
    }

    // Methods

    /** @return the name */
    public String getName() {
        return name;
    }

    /** @return the value */
    public String getValue() {
        return value;
    }

    /** @return the parameters */
    public NVPair[] getParams() {
        return parameters;
    }

    /**
     * Two elements are equal if they have the same name. The comparison is
     * <em>case-insensitive</em>.
     *
     * @param obj
     *         the object to compare with
     * @return true if <var>obj</var> is an HttpHeaderElement with the same name
     *         as this element.
     */
    public boolean equals(Object obj) {
        if ((obj != null) && (obj instanceof HttpHeaderElement)) {
            String other = ((HttpHeaderElement)obj).name;
            return name.equalsIgnoreCase(other);
        }

        return false;
    }

    /**
     * @return a string containing the HttpHeaderElement formatted as it would
     *         appear in a header
     */
    public String toString() {
        StringBuffer buf = new StringBuffer();
        appendTo(buf);
        return buf.toString();
    }

    /**
     * Append this header element to the given buffer. This is basically a more
     * efficient version of <code>toString()</code> for assembling multiple
     * elements.
     *
     * @param buf
     *         the StringBuffer to append this header to
     * @see #toString()
     */
    public void appendTo(StringBuffer buf) {
        buf.append(name);

        if (value != null) {
            if (Util.needsQuoting(value)) {
                buf.append("=\"");
                buf.append(Util.quoteString(value, "\\\""));
                buf.append('"');
            } else {
                buf.append('=');
                buf.append(value);
            }
        }

        for (int idx = 0; idx < parameters.length; idx++) {
            buf.append(";");
            buf.append(parameters[idx].getName());
            String pval = parameters[idx].getValue();
            if (pval != null) {
                if (Util.needsQuoting(pval)) {
                    buf.append("=\"");
                    buf.append(Util.quoteString(pval, "\\\""));
                    buf.append('"');
                } else {
                    buf.append('=');
                    buf.append(pval);
                }
            }
        }
    }
}
